we can't afford four more years of barack obama. >> president obama and governor romney meet in their first-ever presidential debate. watch and engage including the live debate preview at 7:00 p.m. eastern with the debate at 9:00 had posted the day. -- and post-debate. >> i was always shot as anybody that spent a lot of time around campaigns, most people could not explain to me why they did anything they were doing. at some point, they did it because they have always done it that way or there was some sort of role that wasn't really based in any research. i went around the campaigns with skepticism about some of the practices that were taking place. as i learned about people that were doing these field experiments and randomized controlled trials, learning more about the information and targeting based on revolutionizing campaigns in the past decade, this was a major generational shift. in addition to all of these campaigns changing the way they operated, there is cultural tension between the old practices and the new empirical. >> saturday night at 10:00 eastern. he dodged congress m